Janelia Fluor® 646, free acid

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Description: Red dye (Reactive group: free acid). Application: flow cytometry, confocal microscopy, super resolution microscopy (SRM) including dSTORM & STED. Suitable for live cell imaging
Chemical Name: 1-[7-(1-Azetidinyl)-10-(2,5-dicarboxyphenyl)-9,9-dimethyl-9-silaanthracen-2(9H)-ylidene]azetidinium inner salt trifluoroacetate
Purity: ≥95% (HPLC)
Literature (1)

Biological Activity for Janelia Fluor® 646, free acid

Key Information: Janelia Fluor® 646, free acid is a red fluorogenic fluorescent dye; supplied with a free acid reactive group. Suitable for live cell imaging.

Application: Suitable for flow cytometry, confocal microscopy, super resolution microscopy (SRM) including dSTORM (in both live and fixed cells) and STED. Used in protocol (2017 Grimm et al - see references below) for the synthesis of Janelia Fluor® HaloTag® and SNAP-Tag® ligands, for use in live cell imaging experiments. Cell permeable.

Properties and Photophysical Data: Excitation and emission maxima (λ) are 646 nm and 664 nm, respectively; quantum yield = 0.54; extinction coefficient = 152,000 M-1cm-1. A280 correction factor = 0.19; lactone-zwitterion equilibrium constant (KL-Z) = 0.0012.

To measure the absorbance spectrum of this dye we recommend the following solvent: ethanol or trifluoroethanol plus 0.1% TFA.

We also offer Janelia Fluor® conjugated antibodies and custom conjugation services with our sister company Novus Biologicals.

HaloTag is a trademark of Promega Corporation, and SNAP-tag is a trademark of New England BioLabs, Inc.

Licensing Information

Sold under license from the Howard Hughes Medical Institute, Janelia Research Campus

Optical Data for Janelia Fluor® 646, free acid

Janelia Fluor<sup>®</sup> 646, free acid Dye Spectra
Emission Color Red
λabs 646 nm
λem 664 nm
Extinction Coefficient (ε) 152,000 M-1cm-1
Quantum Yield (φ) 0.54
Closest Laser line 640 nm
Reactive Group Free acid
Reactivity Primary amines
Cell Permeable Yes
Correction Factor 280 0.19
Application Flow Cytometry, Confocal Microscopy, dSTORM, STED, Live-cell Imaging
Alternative For Alexa Fluor® 647, Atto 647, Atto 647N, CF640R, CF647, Cyanine 5

Alexa Fluor® is a registered trademark of Molecular Probes, Inc, a Thermo Fisher Scientific Company.

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Use our spectra viewer to interactively plan your experiments, assessing multiplexing options. View the excitation and emission spectra for our fluorescent dye range and other commonly used dyes.

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Technical Data for Janelia Fluor® 646, free acid

M. Wt 610.65
Formula C29H28N2O4Si.CF3CO2H
Storage Store at -20°C
Purity ≥95% (HPLC)
Smiles OC(C1=CC=C(C([O-])=O)C(C(C2=CC=C(N3CCC3)C=C2[Si]4(C)C)=C(C=C/5)C4=CC5=[N+]6CCC\6)=C1)=O.FC(F)(C(O)=O)F

The technical data provided above is for guidance only. For batch specific data refer to the Certificate of Analysis.

Tocris products are intended for laboratory research use only, unless stated otherwise.

Solubility Data for Janelia Fluor® 646, free acid

Solvent Max Conc. mg/mL Max Conc. mM
DMF 12.21 20

Preparing Stock Solutions for Janelia Fluor® 646, free acid

The following data is based on the product molecular weight 610.65. Batch specific molecular weights may vary from batch to batch due to the degree of hydration, which will affect the solvent volumes required to prepare stock solutions.

Select a batch to recalculate based on the batch molecular weight:
Concentration / Solvent Volume / Mass 1 mg 5 mg 10 mg
0.2 mM 8.19 mL 40.94 mL 81.88 mL
1 mM 1.64 mL 8.19 mL 16.38 mL
2 mM 0.82 mL 4.09 mL 8.19 mL
10 mM 0.16 mL 0.82 mL 1.64 mL

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Product Datasheets for Janelia Fluor® 646, free acid

Certificate of Analysis / Product Datasheet
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References for Janelia Fluor® 646, free acid

References are publications that support the biological activity of the product.

Grimm et al (2017) Synthesis of Janelia Fluor HaloTag and SNAP-Tag ligands and their use in cellular imaging experiments. Methods Mol.Biol. 1663 179 PMID: 28924668

Grimm et al (2015) A general method to improve fluorophores for live-cell and single-molecule microscopy. Nat.Methods 12 244 PMID: 25599551

Zheng et al (2019) Rational design of fluorogenic and spontaneously blinking labels for super-resolution imaging. ACS Cent.Sci. 5 1602 PMID: 31572787

If you know of a relevant reference for Janelia Fluor® 646, free acid, please let us know.

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Citations for Janelia Fluor® 646, free acid

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Fluorescent Dyes and Probes Research Product Guide

Fluorescent Dyes and Probes Research Product Guide

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